Plastics generally exhibit low temperature resistance and high thermal expansion compared to metals and ceramics. Thermoplastics in particular are susceptible to high temperatures. The two most common 3D printing technologies - SLS process and FDM process - use such plastics. This makes thermal coating a challenge, as hot spray particles collide against the component surface in the process.
Two opposing material properties, i.e. temperature-sensitive and temperature-requiring, must therefore be combined in the design. Otherwise, with the wrong spraying parameters, the temperature load is too high and the plastic burns superficially - adhesion of the thermal spray coating becomes impossible.
Rybak + Hofmann rhv-Technik has therefore developed a coating system that enables thermal coating of additively manufactured components. This allows metal alloys such as stainless steel and molybdenum as well as hard metals such as tungsten carbide-cobalt or oxide ceramics such as zirconium oxide to be applied to plastics. This allows the advantages of the lightweight 3D printed plastic component to be exploited and its functional optimization to be achieved through wear or temperature-protective layers.
Read the detailed technical article online here- or in the March issue of mo!